add pebble importer (#527)

Merge pull request 527

lib/jekyll-import/importers/pebble.rb

@@ -0,0 +1,97 @@
+module JekyllImport
+  module Importers
+    class Pebble < Importer
+      def self.require_deps
+        JekyllImport.require_with_fallback(%w(
+          nokogiri
+          safe_yaml
+        ))
+      end
+
+      def self.specify_options(c) 
+        c.option "directory", "--directory PATH", "Pebble source directory"
+      end
+
+      def self.process(opts)
+        options = {
+          directory: opts.fetch("directory", "")
+        }
+
+        FileUtils.mkdir_p("_posts")
+        FileUtils.mkdir_p("_drafts")
+
+        traverse_posts_within(options[:directory]) do |file|
+          next if file.end_with?('categories.xml')
+          process_file(file)
+        end
+      end
+
+      def self.traverse_posts_within(directory, &block) 
+        Dir.foreach(directory) do |fd|
+          path = File.join(directory, fd)
+          if fd == '.' || fd == '..'
+            next
+          elsif File.directory?(path) 
+            traverse_posts_within(path, &block)
+          elsif path.end_with?('xml')
+            yield(path) if block_given?
+          else
+          end
+        end
+      end
+
+      def self.process_file(file)
+        xml = File.open(file) { |f| Nokogiri::XML(f) }
+        raise "There doesn't appear to be any XML items at the source (#{file}) provided." unless xml
+
+        doc = xml.xpath("blogEntry")
+
+        title = kebabize(doc.xpath('title').text).gsub('_', '-')
+        date = Date.parse(doc.xpath('date').text)
+
+        directory = "_posts"
+        name = "#{date.strftime('%Y-%m-%d')}-#{title}"
+
+        header = {
+          "layout" => 'post',
+          "title"  => doc.xpath("title").text,
+          "tags"   => doc.xpath("tags").text.split(", "),
+          "categories" => doc.xpath('category').text.split(', ')
+        }
+        header["render_with_liquid"] = false
+
+        path = File.join(directory, "#{name}.html")
+        File.open(path, "w") do |f|
+          f.puts header.to_yaml
+          f.puts "---\n\n"
+          f.puts doc.xpath("body").text
+        end
+
+        Jekyll.logger.info "Wrote file #{path} successfully!"
+      end
+
+      def self.kebabize(string)
+        kebab = '-'.freeze
+        string.gsub!(/[^\w\-_]+/, kebab)
+
+        unless kebab.nil? || kebab.empty?
+          if kebab == "-".freeze
+            re_duplicate_kebab        = /-{2,}/
+            re_leading_trailing_kebab = /^-|-$/
+          else
+            re_sep = Regexp.escape(kebab)
+            re_duplicate_kebab        = /#{re_sep}{2,}/
+            re_leading_trailing_kebab = /^#{re_sep}|#{re_sep}$/
+          end
+          # No more than one of the kebab in a row.
+          string.gsub!(re_duplicate_kebab, kebab)
+          # Remove leading/trailing kebab.
+          string.gsub!(re_leading_trailing_kebab, "".freeze)
+        end
+
+        string.downcase!
+        string
+      end
+    end
+  end
+end